Checker: CSR--EHS: Collaborative Research: Hybrid Timing Analysis via Multi-Mode Execution
- funded by: NSF
(award abstract)
- funding level: $140,000 (for NCSU), $120,000 (for PSU)
- duration: 08/01/2007 - 07/31/2009 (no-cost extension until 07/31/2011)
- PIs: Frank Mueller, Yuan Xie (Penn State)
Current software design for safety-critical embedded systems requires
stringent compliance with coding standards to ensure safety and
reliability. A key additional requirement for real-time embedded
systems is predictable timing behavior of software components, which
requires that bounds on the worst-case execution time (WCET) of
embedded software be determined.
While static timing analysis yields verifiable bounds on the WCET, it
cannot keep pace with architectural innovations and hardware
performance variation due to chip fabrication scaling.
This work contributes a fundamentally new approach to bounding the
WCET with
three major contributions:
1. Instead of simulating execution, actual execution in hardware is
promoted to assess a task's WCET. This approach not only renders
tedious hardware modeling unnecessary but also guarantees correct
behavior regardless of architectural complexity or hardware variation.
2. The approach will be evaluated and its complexity by FPGA
synthesis. This assesses the feasibility of the design and validates a
prototype implementation.
3. The impact of advanced architectural features is studied in
co-design space exploration to providing predictability and tight WCET
bounds.
The proposed research advances existing science and technology through
novel techniques in hardware and software design for safety-critical
embedded real-time systems by
1) providing high-confidence bounds on execution times;
2) enhancing hardware architectures with support to assess execution
times; and
3) customizing hardware features via co-design to improve
predictability.
Publications:
-
"CheckerMode: A Hybrid Scheme for Timing Analysis of
Modern Processor Pipelines Involving
Hardware/Software Interactions"
by S. Mohan and
F. Mueller in Work-in-Progress of
Real-Time Embedded Technology and Applications Symposium, Apr 2007, pages 40-43.
-
"Hybrid Timing Analysis of Modern Processor Pipelines via Hardware/Software Interactions" by S. Mohan and F. Mueller
in Real-Time and Embedded Technology and Applications Symposium, Apr
2008, pages 285-294.
-
"Preserving Timing Anomalies in Pipelines of High-End Processors" by
Sibin Mohan and Frank Mueller
in TR 2007-13, Dept. of Computer Science, North Carolina State
University, May 2008
-
"Merging State and Preserving Timing Anomalies in Pipelines of High-End Processors"
by S. Mohan and
F. Mueller
in Real-Time Systems Symposium, Dec 2008, pages 467-477.
-
"Push-Assisted Migration of Real-Time Tasks in Multi-Core Processors" by
A. Sarkar and F. Mueller
in ACM SIGPLAN Conference on Languages, Compilers, and Tools for
Embedded Systems, Jun 2009, pages 80-89.
-
"CheckerCore: Enhancing an FPGA Soft Core to Capture Worst-Case Execution Times"
by Jin Ouyang, Raghuveer Raghavendra, Sibin Mohan, Tao Zhang, Yuan Xie and Frank Mueller in
Conference on Compiler, Architecture and Synthesis on Embedded
Systems (CASES'09), Oct 2009, (accepted).
-
Making DRAM Refresh Predictable
by B. Bhat, F. Mueller
, Euromicro Conference on Real-Time Systems (ECRTS), Jul 2010,
pages 145-154.
-
Making DRAM Refresh Predictable
by B. Bhat, F. Mueller
in Real-Time Systems Journal, Vol. ??, No. ?, Apr 2011 (accepted), pages ??.
Theses:
"This material is based upon work supported by the National Science Foundation under Grant No. 0720496."
"Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation."